Brandolini, F.; Trombino, L.; Sibilia, E.; Cremaschi, M. (August 2018). "Micromorphology and site formation processes in the Castrum Popilii Medieval Motte (N Italy)". Journal of Archaeological Science: Reports. 20: 18–32. doi:10.1016/j.jasrep.2018.04.017. ISSN2352-409X.
Campopiano, Michele (January 2013). "The evolution of the landscape and the social and political organisation of water management: the Po Valley in the Middle Ages (fifth to fourteenth centuries)". Landscapes or Seascapes?. Comparative Rural History of the North Sea Area. 13: 313–332. doi:10.1484/M.CORN.1.101558. ISBN978-2-503-54058-0.
"Po". United Nations Environment Programme, Division of Early Warning and Assessment (DEWA), Global Resource Information Database (GRID) - Europe. Archived from the original on 1 August 2009. Retrieved 4 June 2009.
"Po". United Nations Environment Programme, Division of Early Warning and Assessment (DEWA), Global Resource Information Database (GRID) - Europe. Archived from the original on 1 August 2009. Retrieved 4 June 2009.
Squatriti, Paolo (2002). Water and society in early medieval Italy, AD 400-1000. Cambridge: Cambridge University Press. ISBN978-0521522069. OCLC49550805.
Brandolini, F.; Trombino, L.; Sibilia, E.; Cremaschi, M. (August 2018). "Micromorphology and site formation processes in the Castrum Popilii Medieval Motte (N Italy)". Journal of Archaeological Science: Reports. 20: 18–32. doi:10.1016/j.jasrep.2018.04.017. ISSN2352-409X.